FIG. 1 shows a traditional connection between windings 2 of a stator of an electric machine such as a generator and phase connections 4 (phase rings).
This connection typically comprises a conductive element 3 brazed at one side to the winding 2 and at the other side to the phase connection 4.
Above the winding 2 end, conductive element 3 and phase connections 4 end an insulating cap 5 is provided to insulate and protect the components housed therein.
As shown, traditional caps 5 are made as two elements; a first element 6 that houses the winding 2 end and the greatest part of the conductive element 3, and a second element 7 that envelopes the phase connection 4 end and has its ends that overlap the borders of the first element 6 at the zones 8.
Putty 9 is also provided within the first and second elements 6, 7 to mechanically fix the cap 5 and electrically insulate the components housed therein.
These caps 5 proved to be very efficient and provide an excellent insulation, but in some cases, their use could be troubling.
In fact, the minimum distance between two adjacent caps 5 must be large enough to avoid discharges (this is the so called electric distance that depends on the materials, voltage, etc).
With the described traditional caps, the minimum distance is much smaller than desirable because of the overlapping of the second parts 7 on the first parts 6 of the caps 5. This causes large constraints in the machine design (for example with reference to the number of slots housing the windings) or maximum voltage achievable.
In addition, an upgrade of a machine such as an electric generator (by increasing the operating voltage) would not be possible, because the upgraded voltage would be too high for the actual distances between adjacent caps 5.
Moreover, assembling of the two pieces 6, 7 of the caps 5 and at the same time the application of putty is typically very time consuming.